www.nature.com/scientificreports
OPEN
received: 05 March 2016 accepted: 10 May 2016 Published: 31 May 2016
Spartina alterniflora invasion alters soil microbial community composition and microbial respiration following invasion chronosequence in a coastal wetland of China Wen Yang1, Nasreen Jeelani1, Xin Leng1, Xiaoli Cheng2 & Shuqing An1 The role of exotic plants in regulating soil microbial community structure and activity following invasion chronosequence remains unclear. We investigated soil microbial community structure and microbial respiration following Spartina alterniflora invasion in a chronosequence of 6-, 10-, 17-, and 20-year-old by comparing with bare flat in a coastal wetland of China. S. alterniflora invasion significantly increased soil moisture and salinity, the concentrations of soil water-soluble organic carbon and microbial biomass carbon (MBC), the quantities of total and various types of phospholipid fatty acids (PLFAs), the fungal:bacterial PLFAs ratio and cumulative microbial respiration compared with bare flat. The highest MBC, gram-negative bacterial and saturated straight-chain PLFAs were found in 10-year-old S. alterniflora soil, while the greatest total PLFAs, bacterial and gram-positive bacterial PLFAs were found in 10- and 17-year-old S. alterniflora soils. The monounsaturated:branched PLFAs ratio declined, and cumulative microbial respiration on a per-unit-PLFAs increased following S. alterniflora invasion in the chronosequence. Our results suggest that S. alterniflora invasion significantly increased the biomass of soil various microbial groups and microbial respiration compared to bare flat soil by increasing soil available substrate, and modifying soil physiochemical properties. Soil microbial community reached the most enriched condition in the 10-year-old S. alterniflora community. Plant invasion, one component of anthropogenic-induced global change, has caused severe biological impacts on native ecosystems and great economic costs1 by changing the composition of species and the ecosystems’ structure2, processes and functioning3,4. Alterations in plant community structure may affect composition of soil microbial community and functioning by altering the quality and quantity of litter input and by modifying soil physical, chemical and biological environment5. Numerous studies have reported that plant invasion can alter the composition of the soil microbial community6–8, stimulate or inhibit microbial activity9,10, and change many important nutrient cycling processes and pools4,11. Nevertheless, our understanding of soil microbial community structure and activity as affected by plant invasion is still limited, particularly for different plant invasion chronosequences. Plant invasion can influence soil microbial community structure and activity by altering the quantity and/or quality of litter entering the soil11,12. Previous studies have found that plant invasion can change aboveground (leaf litter) and belowground (root litter and exudates) inputs13,14. Elgersma et al.8 have reported that the alterations in the soil microbial community are mainly driven by belowground processes (e.g., belowground inputs) rather than aboveground litter inputs8. Plant invasion also shifts the resources available to soil microorganisms and 1
School of Life Science and Institute of Wetland Ecology, Nanjing University, Nanjing 210093, P. R. China. 2Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, P. R. China. Correspondence and requests for materials should be addressed to X.L. (email: lengx@ nju.edu.cn) or X.C. (email: [email protected]) Scientific Reports | 6:26880 | DOI: 10.1038/srep26880
1
www.nature.com/scientificreports/ Moisture (%)
pH
Salinity (%)
SOC (g kg−1)
19.67 ± 0.37
8.87 ± 0.02
0.66 ± 0.04
0.95 ± 0.02
28.33 ± 0.34
0.219 ± 0.035
6 years
45.45 ± 0.86b
8.48 ± 0.04c
1.82 ± 0.20b
10.07 ± 1.01b
55.62 ± 0.38b
1.019 ± 0.168a
1777 ± 137c
5530 ± 468a
10 years
46.57 ± 0.47
8.59 ± 0.03
1.85 ± 0.17
10.25 ± 1.92
61.92 ± 1.74
1.058 ± 0.245
1845 ± 138
5808 ± 601a
17 years
52.54 ± 0.39
8.46 ± 0.03
1.78 ± 0.10
15.56 ± 0.50
62.14 ± 1.01
1.357 ± 0.039
a
3009 ± 175
5291 ± 269a
20 years
51.17 ± 0.33a
8.54 ± 0.03bc
2.23 ± 0.07a
11.92 ± 0.64ab
47.74 ± 1.19c
1.135 ± 0.039a
2330 ± 116b
5435 ± 707a
Bare flat
c
a
c
c
WSOC (mg kg−1) d
SON (g kg−1) b
Aboveground biomass (g m−2)
Root biomass (g m−2)
–
–
S. alterniflora b a
b c
b b
b a
a a
a a
c
Source of variation Invasion time
***
***
***
***
**
**
***
n.s.
Table 1. Soil (0–30 cm depth) and plant properties (mean ± SE, n = 9) following S. alterniflora invasion in a coastal wetland of China. Different letters indicate statistically significant differences at α = 0.05 level across the S. alterniflora invasion chronosequence. **P
OPEN
received: 05 March 2016 accepted: 10 May 2016 Published: 31 May 2016
Spartina alterniflora invasion alters soil microbial community composition and microbial respiration following invasion chronosequence in a coastal wetland of China Wen Yang1, Nasreen Jeelani1, Xin Leng1, Xiaoli Cheng2 & Shuqing An1 The role of exotic plants in regulating soil microbial community structure and activity following invasion chronosequence remains unclear. We investigated soil microbial community structure and microbial respiration following Spartina alterniflora invasion in a chronosequence of 6-, 10-, 17-, and 20-year-old by comparing with bare flat in a coastal wetland of China. S. alterniflora invasion significantly increased soil moisture and salinity, the concentrations of soil water-soluble organic carbon and microbial biomass carbon (MBC), the quantities of total and various types of phospholipid fatty acids (PLFAs), the fungal:bacterial PLFAs ratio and cumulative microbial respiration compared with bare flat. The highest MBC, gram-negative bacterial and saturated straight-chain PLFAs were found in 10-year-old S. alterniflora soil, while the greatest total PLFAs, bacterial and gram-positive bacterial PLFAs were found in 10- and 17-year-old S. alterniflora soils. The monounsaturated:branched PLFAs ratio declined, and cumulative microbial respiration on a per-unit-PLFAs increased following S. alterniflora invasion in the chronosequence. Our results suggest that S. alterniflora invasion significantly increased the biomass of soil various microbial groups and microbial respiration compared to bare flat soil by increasing soil available substrate, and modifying soil physiochemical properties. Soil microbial community reached the most enriched condition in the 10-year-old S. alterniflora community. Plant invasion, one component of anthropogenic-induced global change, has caused severe biological impacts on native ecosystems and great economic costs1 by changing the composition of species and the ecosystems’ structure2, processes and functioning3,4. Alterations in plant community structure may affect composition of soil microbial community and functioning by altering the quality and quantity of litter input and by modifying soil physical, chemical and biological environment5. Numerous studies have reported that plant invasion can alter the composition of the soil microbial community6–8, stimulate or inhibit microbial activity9,10, and change many important nutrient cycling processes and pools4,11. Nevertheless, our understanding of soil microbial community structure and activity as affected by plant invasion is still limited, particularly for different plant invasion chronosequences. Plant invasion can influence soil microbial community structure and activity by altering the quantity and/or quality of litter entering the soil11,12. Previous studies have found that plant invasion can change aboveground (leaf litter) and belowground (root litter and exudates) inputs13,14. Elgersma et al.8 have reported that the alterations in the soil microbial community are mainly driven by belowground processes (e.g., belowground inputs) rather than aboveground litter inputs8. Plant invasion also shifts the resources available to soil microorganisms and 1
School of Life Science and Institute of Wetland Ecology, Nanjing University, Nanjing 210093, P. R. China. 2Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, P. R. China. Correspondence and requests for materials should be addressed to X.L. (email: lengx@ nju.edu.cn) or X.C. (email: [email protected]) Scientific Reports | 6:26880 | DOI: 10.1038/srep26880
1
www.nature.com/scientificreports/ Moisture (%)
pH
Salinity (%)
SOC (g kg−1)
19.67 ± 0.37
8.87 ± 0.02
0.66 ± 0.04
0.95 ± 0.02
28.33 ± 0.34
0.219 ± 0.035
6 years
45.45 ± 0.86b
8.48 ± 0.04c
1.82 ± 0.20b
10.07 ± 1.01b
55.62 ± 0.38b
1.019 ± 0.168a
1777 ± 137c
5530 ± 468a
10 years
46.57 ± 0.47
8.59 ± 0.03
1.85 ± 0.17
10.25 ± 1.92
61.92 ± 1.74
1.058 ± 0.245
1845 ± 138
5808 ± 601a
17 years
52.54 ± 0.39
8.46 ± 0.03
1.78 ± 0.10
15.56 ± 0.50
62.14 ± 1.01
1.357 ± 0.039
a
3009 ± 175
5291 ± 269a
20 years
51.17 ± 0.33a
8.54 ± 0.03bc
2.23 ± 0.07a
11.92 ± 0.64ab
47.74 ± 1.19c
1.135 ± 0.039a
2330 ± 116b
5435 ± 707a
Bare flat
c
a
c
c
WSOC (mg kg−1) d
SON (g kg−1) b
Aboveground biomass (g m−2)
Root biomass (g m−2)
–
–
S. alterniflora b a
b c
b b
b a
a a
a a
c
Source of variation Invasion time
***
***
***
***
**
**
***
n.s.
Table 1. Soil (0–30 cm depth) and plant properties (mean ± SE, n = 9) following S. alterniflora invasion in a coastal wetland of China. Different letters indicate statistically significant differences at α = 0.05 level across the S. alterniflora invasion chronosequence. **P
